Along with the progress of miniaturization of LSIs, problems such as signal transmission delay, reliability of signal lines, signal interference, increase in power consumption have become evident in the electric wiring technique. Application of optical wiring to signal transmission in an LSI chip has been studied to solve these problems. For example, Non-Patent Document 1 discloses an example using the optical wiring for the signal transmission within an LSI chip. In an LSI optical interconnection structure in this document, surfaces of an LSI chip and an optical interconnection chip are bonded together. This bonded structure is able to achieve a high-performance chip with almost no change of a related LSI design rule and a manufacturing process, because the LSI chip and the optical interconnection chip are separately manufactured.
Patent Document 1 discloses a structure using light for the signal transmission between laminated LSI chips. The use of wavelengths at which a substrate constituting a chip becomes transparent enables data transmission between laminated LSI chips.
Patent Document 2 discloses an inductive coupling system which enables signal transmission in a non-contact manner. The use of the inductive coupling system makes it possible to perform highly efficient signal transmission between the LSI chips in a laminating direction in a non-contact manner without necessity to form a direct electric connection.
In general, there is known a method for transmitting signals between laminated LSI chips by forming a through-hole in a laminated SIP (System in Package).
[Patent Document 1] Japanese Patent No. 3413839 (page 4, FIG. 4)
[Patent Document 2] Japanese Unexamined Patent Application Publication No. 2005-228981 (page 4, FIG. 1)
[Non-Patent Document 1] Keishi Ohashi, “On-chip Optical Interconnect Technology”, 2007 Semiconductor MIRAI project results debriefing session, Semiconductor MIRAI project publication, Dec. 18, 2007, page 82.